Apparatus for testing locomotives



March 25, 1941. w. F. coLLxNs APPARATUS FOR TESTING I IOCOMO'IIVES- Fileduuly 2o,4 193s s sheets-sheet 1 ATTO R N EYS W. F. COLLINS APPARATUS FOR TESTING LOCOMGTIVES March 25, 1941.

Filed July 20, 1938 3 Sheets-Sheet 2 INVENTOR ATTORNEYS Filed July 2o, 193s 3 Sheets-Sheet 5 By mymm ATTO R N EYS Patented Mar. 25, 1941 UNITED s'rA'rris APPARATUS Fon 'rEs'riNGgnoooMo'rIvEs' walter rroolli'ns, scandale, N. Y.

Application July 2o, 193s, serial No. 220,406

4 Claims.

This invention relates to apparatusfor testing locomotives.

In locomotive testing, a laboratory locomotive is utilized, to determine among other things boiler efficiency, merits of anyparticular device or appliance, and economic value of fuel and its relation to boiler capacity. y'Three conventional test methods are in use, first, roadtests involving the use of a dynamometer car and under road service conditions; Second, stationary dynamometer tests in which the locomotive machinery is run and the locomotive is worked throughout its range of its capacity, while the locomotive remains stationary.' This permits all test measurements to be made with a degree of accuracy possible only in a stationary power plant. The stationary dynamometer test requires a special building, housing a meansfor supporting the locomotive so that its driving wheels may be rotated and the power absorbed and dissipated, together with a locomotivestationary dynamometer. Third, standing tests in which the machinery is disconnected and the boiler alone is operated, the steam generated being passed through the exhaust nozzle to produce the draft in the usual way. I

Road tests are diicult to conduct, are costly and have a bad eect on operation due to steam failures, slow train movements, stalled trains and bad psychological effect on engineers and remen. Stationary dynamometertests are costly and few plants Aare built in this country and abroad, and these are not readily available to all railroads. Standing tests are generally resorted to in an endeavor to avoid the above trying experiences and high costs. In a standing test the valves and the cylinde pistons are removedV and the cylinder acts as expansion chamber. Highly superheated steam is admitted to the cylinder at reduced pressure equal to the exhaust pressure, through the mediumof a gate valve.` These standing tests are inaccurategand do not simulate actual road conditions becauseY boiler pressure is reduced to the proper exhaust or back pressure and no control of temperature is attempted. l

In the operation of a'locomotive in actual service a 'large portion of the energy of the steam is converted into w'ork'by the operation of the pistons and associated' parts, resulting in a decrease in the pressure and temperature of the steam flowing through the system. Other losses by radiation and other causes also diminish the potential energy of the steam and the total energy loss is determined in road tests by a. comparison vof the' temperature, pressure andquality of the steam, before entering and after passing through thecylinders as determined by instruments such as thermometers, pressure gages, calorimeters and the like.

Heretofore standing tests of locomotives have attempted the control of the pressure at the exhaust nozzle only, so vthat the escaping steam Acontainsiall the energy that in road operation is ldissipated in the form of work, and as the amount of gas expelled frrom the smokebox by the exhaust nozzle and stack combination depends on the energy in the steam supplied rather than its weight, the results lhave been mislead'- mg. i

In the operation of modern locomotives, the u' expansion of the steam inthe `cylinder is rarely carried to the point Where saturation temperatures are reached or moisture lexists in the exhaust steam, hence I have discovered that in the simulationv of road conditions during a standing. test .it is only necessary to reduce the intrinsic L energy of the steam by. desuperheating as described, and abstract from the system'an amount of steam equivalent to the water usedl for When the temperature of the exhaust steam is not controlledand the steam possesses a high degree of superheat, the steam exhibits a greater volume for a given back pressure than when it is used in the cylinders to work the pistons of a locomotive. This excess volume produces high velocity indraft through the stack resulting in large quantities of excess air passing through the boiler, and effecting the boiler eiciency and capacity' so that road conditions are not even approximately simulated.

With the above in mind an object of the present invention is to provide, in a standing test, apparatus for controlling the temperature of the exhaust steam by desuperheating the superheated steam, through the medium of a spray of water mist in the cylinder and which is subsequently removed in its entirety. The standing test, with exhaust temperature thus controlled in accordance with the invention, produces a quicker, more accurate and economical method for studies than hitherto possible because uniformity of conditions can be maintained, the eiect of minor changes can be observed, a great many more tests may be made in a given time than hitherto possible, and the actual road performance can be predicted, in the laboratory, without incurring either the difficulties of procedure or the uncertainty of road tests.

With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims Without departing from the spirit or sacrificing any of the advantages of the invention. l

In the accompanying drawings forming part of this specification,

Figure 1 is a fragmentary side elevation of a laboratory steam locomotive, with parts in section, equipped With apparatus for desuperheating the steam and controlling exhaust temperature, in accordance With the invention.

Figure 2 is a front elevation of the locomotive shown in Figure 1.

Figure 3 is a detail longitudinal sectional view taken on the line 3 3 of Figure 1.

Figure l is a detail longitudinal sectional View of the locomotive cylinder showing the location of the Water spray nozzlesfor desuperheating the steam.

Figure is a cross sectional view taken on the line 5-5 of Figure 4.

Figure 6 is a detail cross sectional View showing a modied form of the invention.

Referring now to the drawings in which like characters of reference designate similar parts in the various views, I il designates a stationary locomotive in which the pistons have been removed from the cylinders I I and the valves have been removed from the Valve chests I2. In carrying out the invention a tube I`3 is disposed axially in each valve chest and discs I4 are Welded to the ends of the tube and to the valve bushings I5 in such manner that each tube and its discs permits some of the exhaust steam to pass from the respective cylinder through the front exhaust passagetvays I6 of the valve chest, as indicated by arrows, and the remaining portion to pass through the rear exhaust passageways I1, of the valve chest, as also indicated by arrows, thus reducing pressure.

The tube and discs separate and prevent leakage between superheated steam which enters the valve chest from the steam pipe I8 and passes into the cylinder` through the passageways I9 and 2U, and the steam, desuperheated by the hereinafter described water spray, which exhausts from the cylinder through the exhaust passage- Ways of the valve chest and through the exhaust passageways I6, tube I3 and exhaust passageways I1 of the valve chest. The steam admitted to the valve chest through a valve 2I in the steam pipe I 8, is highly superheated steam reduced in pressure to that of the exhaust steam in a road test.

A plurality of spray nozzles 22 are arranged in stepped relationship in each cylinder II and the respective pipes 23 from the nozzles are conducted through stuiing boxes 24 in the rear head 25 of the cylinder. The pipes are controlled by respective valves 25 and communicate with a water manifold 21 which is supplied with water through a pipe 28 which is equipped with a Water meter 29. A pressure gauge 30 is connected to the Water manifold. The highly superheated steam in the cylinder meets the Water from the spray nozzles and ashes the Water into steam. The water absorbs heat from the superheated steam and reduces the temperature of the steam, that is, desuperheats the steam. rIhe temperature of the desuperheated steam exhausting from the cylinder through the passageways 2 may be controlled tov any predetermined degree, and is determined by the amount of water added to the steam by the sprays.

The additional steam created by the water spray must be bled oiI or extracted to attain results equivalent to a road test. Obviously any increased amount of steam passing through the exhaust nozzle would increase the draft and increase thevolume of air drawn into the iire box for combustion so that the boiler performance would not duplicate a road test.

For removing this excess steam created by the Water spray, a bleed olf or steam extraction pipe 3| is connectedto the front and rear exhaust passages 32, best shown in Figures 2 and 3, which lead from the cylinders to the exhaust pipe and nozzle 33. AIn practice, an amount of steam equal to the spray water, indicated by the meter Z9, is lead away through the pipe 3| and diverted from the exhaust nozzle. The quantity of steam bled off is controlled by a valve 34 in the bleed oi pipe, best` shown in Figure 1. A pressure gauge4 35' and a thermometer 36 are located in the bleed 01T pipe or other suitable location in the system, to indicate respectively the pressure and the temperature of steam passing to the exhaust nozzle'.

By `manipulation of the valves 25, arranged for operation using any number at one time, and regulating pressure of the Water to obtain the best spray for the best temperature results, steam, at pressure and temperature corresponding to the pressure and temperature experienced in a road test, and at the same volume, may be delivered to the exhaust pipe and nozzle for the creation of draft, and for the purpose of furnishing air for combustion in the lire box and expelling the products of combustion, such as gases, cinders and smoke, together With the exhaust steam to the atmosphere, by Way of the stack 3l.

In Figure 6 there is shown a modified form of the invention in which the parts are the same as above described with the exception that instead of using the tube I3 and discs I4 the conventional piston valve 38 is blocked in the valve chest so that the desuperheated steam divides and part passes through the front exhaust passageway 39, and part passes through the piston valve body to the rear exhaust passageway di?.

In operation, superheated steam designated as 100% at' the steam pipe I8, is admitted to the valve chest I'2 and from there passes through the valve bushing at the rear end of the valve chest and into the cylinder where it encounters ,the sprays. and is reduced in temperature or desuperheated. The sprays add an X amount of Water and the 100% steam plus an X amount, which has been flashed into steam from the Water, passes from the cylinder, part of the steam passing through the valve bushing at the front end of the valve chest and into the front exhaust passages, and part passing through the tube I3 and through the rear valve bushing and into the rear exhaust passages.

The purpose of directing the exhaust steam through both the front and the rear exhaust passages is to reduce the exhaust pressure in a manner similar to that which takes place in actual road service when the valve spool is working and the steam is being used to drive the drive wheels.

From the exhaust passages 32 the steam divides, part passing to the exhaust nozzle and part passing into the bleed off pipe 3i where an X amount. of steam is extracted or bled oi in order that only the steam originally furnished by the boiler, will go through the exhaust nozzle. This arrangement duplicates exactly the conditions that take place when steam is used during actual road service, or during road tests, or during stationary tests when the pistons are used to convert the energy of the steam into work.

While the invention has been described in connection with locomotive testing, the scope of the invention is intended to extend to industrial processes wherever there is a need for low temperature steam initially furnished at high temperatures.

From the above description it is thought that the construction and operation of the invention will be fully understood without further explanation.

What is claimed is:

1. Apparatus for simulating actual road performance in the standing test of a locomotive having a boiler, a cylinder, a valve chest, a connection between the boiler and valve chest, front and rear exhaust passages, a connection between the exhaust passage and the valve chest, and an exhaust nozzle, comprising the combination of means for supplying a predetermined quantity of water to the cylinder for reducing the temperature of superheated steam in the cylinder, means in the valve chest for initially supplying superheated steam to the cylinder at one end thereof and subsequently directing the steam,

together with an added amount of steam flashed from the water, from the opposite end of the cylinder to both the front and the rear exhaust passages simultaneously to reduce pressure of the steam, means connected to the exhaust passages for extracting an amount of steam equal to the steam ilashed from the Water, and means for delivering the resultant steam to the exhaust nozzle.

2. Apparatus for simulating actual road performance in the standing test of a locomotive having a boiler, a cylinder, a Valve chest, a connection between the boiler and valve chest, front and rear exhaust passages, a connection between the exhaust passages and valve chest, and an exhaust nozzle, comprising the combination of a spray nozzle in the cylinder, a water supply pipe connected to said nozzle, a meter for measuring the Water supplied to the nozzle through the pipe, said valve chest having valve bushings, a stationary valve connected to the valve bushings of the valve chest and adapted to supply superheated steam to one end of the cylinder and divide desuperheated steam from the opposite end of the cylinder into two paths respectively to the front and to the rear exhaust passages, a valve controlled bleed off pipe connected to the exhaust passages for extracting an amount of steam equal to the steam flashed from the water, and means for delivering the resultant steam to the exhaust nozzle.

3. Apparatus for simulating actual road performance in the standing test of -a locomotive having a boiler, a cylinder, a valvechest., ra connection between-the boiler and valve chest, front,

and rear exhaust passages, a connection between the exhaust passages and valve chest, and an exhaust nozzle, comprising the combination of a spray nozzle in the cylinder, a valve controlled Water supply pipe connected to said nozzle, a meter for measuring the water supplied tothe nozzle through the pipe, said valve chest having bushings, a stationary valve connected to the valve bushings of the valve chest and adapted to supply superheated steam to one end of the cylinder and divide desuperheated steam from the opposite end of the vcylinder into two paths respectively to the front and to the rear exhaust passages, a valve controlled bleed oi pipe connected to the exhaust passages for extracting an amount of steam equal to the steam flashed from the water, a thermometer and a pressure gauge connected to the bleed off pipe for indicating the temperature and pressure of steam therein, and means for delivering steam at the pressure and temperature indicated by the thermometer and the pressure gauge to the exhaust nozzle.

4. Apparatus for simulating actual road performance in the standing test of a locomotive having a boiler, a cylinder, a valve chest, a connection between the boiler and valve chest, a connection between the exhaust passages and valve chest, and an exhaust nozzle, comprising the combination of means for admitting steam under pressure above atmosphere and temperature above saturation to the locomotive cylinder, means for introducing a spray of water into the locomotive cylinder, means for extracting the steam ashed from the water spray, which extracted steam represents the heat drop or thermal value of the steam equalized in the cylinder where part of its thermal value or energy is transformed into mechanical energy and transmitted to the drive wheels during actual service conditions, means for passing exhaust steam to the main exhaust passages of the locomotive for draft making purposes subsequent to extraction of the quantity of steam flashed from the water spray, and meansfor determining the temperature and the pressure of the exhaust steam.

WALTER. F. COLLINS. 

